Method of vulcanizing pneumatic tubes



W. L. FAIRCHILD.

METHOD OF VULCANIZING PNEUMATIC TUBES.

APPLICATION FILED SEPT 3, I920.

Patented July 25, 1922.

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METHOD OF VULCAINIZING PNEUMATIC TUBES.

Specification o aaeareo.

fLetters Pate t. Patented anal se, rose.

Application filed September 3, 1920. Serial No. 408,017.

To all whom it may 00mm:

Be it known that I, WALTER L. FArncHILo, residing at New York, in the county "and State of New York, have invented certain new and useful Improvements in a Method of Vulcanizing Pneumatic Tubes, of which thefollowing is a specification.

This invention relates to a new and improved method of vulcanizing, more parties ularly to a method of vulcanlzing tubes for neumatic tires and the like, and the prime object of the invention is to provide a new and improved process for controlling the pressure and temperature within the molds during the vulcanizing operation,

Another object of the invention is to provide a new and improved method of freeing or loosening the product from the interior of the molds, and also whereby any obnoxious or poisonous gases utilized in the vulcanizingprocess are discharged to theatmosphere.

Uther objects and aims of the invention, more or' less specific than those referred to above, will be in part obvious and in part pointed out in the course of the following description of my improved method, and of the steps, and of the relation of each of the steps to one or more ofthe others thereof employed in carrying out my method, and the scope of protection contemplated will be indicated in the appended claims.

In the ac'companying'drawing wherein I have illustrated a preferred form ofapparatus for carrying out my invention,

c Figure 1 is the schematic view, partly illustrating in section the manner of carrying out my impnoved' method, an

Fi re 2 is a vertical sectional' view taken through the apparatus for carrying out the said process, said view beingtaken on line 22' of Figure 1, looking in the direction Referring now to the drawings, wherein similar reference characters refer to similar parts inboth views thereof the reference 1 denotes a steam chest or vulcanizer, the same cylindrically-formed walls 2 and 3,. the latter being preferably removable for a purpose which will be presently explained, Located within the con"- tainer are tracks ,4 and 5 adapted to receive the wheels 6 and truck or jmould carriage 7. The carriage 7 is providedwith a'plurality of longitifdinally extending members 8 and 9' which carry a plurality of opensided semi-circular members 11, the latter being so connected with the. longitudinally extending members 8 and 9 so that a rigid superstructure is provided for-the carriage. The semi-circularopen-sided members 11 are spaced apart and are disposed in parallel vertical planes, the open-ended sides thereof being uppermost so that each of said members provides a pocket adapted for receiving one of the moulds 12.

The moulds 12 in the present instance comprise circular hollow receptacles, each of which is formed in sections, the construction being such that when the sections are disconnected the tube upon which the vulcanizing operation is to be effected can be inserted therein, whereby when the sections ofthe moulds are united by clamping means (not shown), it being understood that the construction of the moulds is. such that a gastight fit is established between the points of I,

jointure-of said sections.

.Extending in parallel relation with the sides of the longitudinally extending members or'braces 8 and 9is a tube 13, said tube being carried upon, brackets 14 supported exteriorl-y of the pocket members 11, one end of said tube being closed as at 14 and the opposite end being connected by means of the'flexible connection 15 with a source of gas supply presently to be explained.

Leading into the vulcanizer 1 is a conduit i .1 7, valved as at 18, and leading out of said container is aconduit 19 valved as at 20.

Conduit 17 leads froma suitable source of steam supply (not shown) the conduit 19 operates as a dlscharge conduit.

At his point it may be noted that as is usual in vulcanlzing apparatus the conduits 17 and 1.9 are utilized for the purpose of maintaining such head of steam within the vulcanizer as will maintain the interior of the latter at the desired temperature to be utilized in carrying out the vulcanizing process, the temperature being increased or diminished bv a regulation of the steam pressure within the vulcanizen.

21 denotes a tank or container adapted to receive a gas such as air or, in fact any gaseous minture,'which ma be found desirable in assisting in the vu caniaing process.

\ Leading I at 23. This conduit 22 leads from a suitable source of air or gas provided with a pump adapted to maintain a supply ofi-air or gas under pressure in the tank 23.

lie

" 36 valved as at 37. The conduit 3 .bein as will permit the carriage to be removed 24 denotes a heater or burner disposed underneath the tank 21" through the instrumentality of which any desired temperature may be maintained in the air or aseous mixture within the tank 21. Suita le pressure and temperature gauges or indicators are shgwn respectively at 25 and 26 upon the container 1.

Leading from the container 21 is a conduit 27 valved as at 28, said conduit in the resent instance leading into the fitting 29. ading from the fitting 29 is a conduit 30, the latter leading to and-bein'g connected with the flexible conduit 15. A pressure gauge 31 is provided in the conduit 30.

The reference numeral 32-, indicates a vacuum tank in which a vacuum of any desired degree may be maintained by means of suction applied to the conduit 33, the conduit 34 connecting the vacuum tank 32 with the fitting 29, said conduit 34 being valved as at 35. 7

Leading from the fitting 29 is a onduit leads into the atmosphere and it is intended that the same shall be so disposed that the exit end thereof will be in a point remote from the. apparatus, so that any obnoxious or poisonous gases may be discharged into the atmosphere without danger of injury ,to the operatives of the apparatus. Locatediexteriorly of the vulcanizer: are tracks 38, the latter being disposed in parallel relation with the tracks 4and 5, so that when the end wall or door 3 of the vulcan izerl is removed the truck or carriage for the moulds may be rolled out on to the tracks 38, the flexible conduit 35 being either long enough to permit of the removal of the truck 31, or such detachable connection provided for the flexible conduit 15 from its vulcanizer.

The conduit 13 is provided with a plurality of branches 39, each of which is valved as'at 40, said branches 39 being preferabl rigidly supported upon the conduit -13. *ach of the, branches 39 is'provided with a flexible tube 41 which connects with the valve stem 42 of each of the tubes within the mould 12. 'A. detac haole connection 43 is provided upon the tubes 4:1 which connects tubes with the valve stems.

At-this point it may be noted that the check valve usually employed in valve stems is omitted during the vulcanizing operation, the valves 0 rating to maintain the pressure within t e tubes in'the mould.

In the drawing I have shown the tube' 13 throughwhich the air or gases to be utilized in the vulcanizing of thetubes operation must pass. This tube being located within the vulcanizer insures a heating of the gases passing into the interior of the-tubes to a temperature equal to thatsurrounding the starting the vulcanizing operation, the door of the vulcanizer l'is removed or swung open so that the carriage carrying the moulds may be moved upon the. tracks 38. The moulds carrying the tubes to be vdlcanized are next inserted in the respective pockets or receptacles 11. During ,this operation the valves 40 are open so that when the air or other gas to be used in carrying on the vulcanizing process are liberated from the tank 21, they will be discharged into the tubes within the moulds. the full number of moulds is notto be utilized, such valves 40 whose branches would ordinarily lead to the moulds are closed, thus preventing a discharge of the air or other vulcanizing gases into the interior of the. vulcanizer. a

When .the several moulds have been connected with'the conduit 13, the truck carryingall the moulds is run into the vulcanizer and door 3 thereof closed. The valve. 28 is In the event that then opened, it being understood that-the valves 35 and 37 are in closed positions, permitting the air or vulcanizing gases from the tank 21 to pass into the tube. The initial pressure maintained in the tubes in the mould is of course less than the ultimate pressure will be, due tothe heating of the moulds by the steam within the vulcanizer.

It will be seen by the arrangement just described that any gas desired to be utilized in the vulcanizing process may be dischairlged from the tubes by the supply tank -21. aving'arranged the truck within the vulcanizer as shown, the steam is let into the said vulcanizer through the said conduit 17 and valve 18, such a pressure being maintained within the vulcanizer as will maintain the ,moulds at the required vulcanizing tem- Inasmuch as the air or"other perature. gases which ass into the tube, 'ass through the coil 13 t e temperaturewit in the tubes may if desired be kept equal to that of the temperature without the moulds. It will be noted, however, that the temperature of the air or gases within the tubes may be raised or lowered relative to the exterior pressure by regulating the burner 24. When the vulcanizlng operation has been completed with-' in the vulcanizer, the valve 28 is closed and the valve 37 opened, whereby the gases 10:

its,

cated within the tubes of the moulds can be discharged into the atmosphere. If it is then desired to loosen the tubes from the interior walls of the moulds, the valve 37 may be closed and the valve opened, thereby'subjecting the interior of the tubes to a negative pressure-the effect of which is to contract the tubes and close them, to be separated from the walls of the moulds.

If desired, the valves 35 and 28 may be alternately opened and closed, causing the tubes within the moulds to be vibrated,

"whereby they may be thoroughly and comprovided a method well adapted, among others, to obtain all the ends and objects above set forth, in an exceedingly and efliciently simple manner. The means of my improved method and exact pressure and temperature may be maintained both 'interiorly and exteriorly of the tubes being vulcanized. Moreover, any desired gas which may be useful in the moulding operation may be easily projected within the tubes. For instance it may be desirable in some cases to project steam within the tubes being vulcanized, or a mixture of steam, and the vapors of other substances, where by all of the material of the tube may be more thoroughly subjected to the vulcaniz; ingj operation.

he elimination of the usual check valve provided, in the valve stems also effects a saving, inasmuch as these valves are ordinarily injured by being subjected to the heat of vulcanization.

As manychanges could be made in this construction without departing from the scope of the following claims, it is intended that allmatter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative.

only and not in a limiting sense.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

1. The method of vulcanizing rubber tubesconsisting in encasing them' in suitable molds and subjecting the same to the heat of steam applied to them externally in a closed steam chest-, and applying gaseous pressure to the tubes interiorly at the same time, and then connectingthe interiors of the vulcanized tubes with a vacuum tank to free them from the molds.

2. The method of vulcanizing rubber I tubes consisting in encasin'g them in suitable molds and subjecting the same to the heat of steam applied to them externally in a closed steam chest, and applying hot gaseous pressure to the tubes interiorly, and then connecting the interiors of the vulcanized tubes with a vacuum tank to free them from the molds.

3. The method of vulcanizing rubber tubes consisting in encasing them in suitable molds and subjecting the same to the heat of steam applied externally to them in a closed steam chest, and applying gaseous pressure to the interiors of the tubes at-the same time, and

connecting the vulcanized tubes alternately witha pressure tank and with a vacuum tank to free the tubes from the molds.

In testimony whereof I .afiix my signature in the presence'of two witnesses.

- WALTER L. FAlRC-HILD. Witnemes: j

EMMA WEINBERG, IRVING A. HAMER. 

